This call changes the size of memory originally allocated by DosAllocHuge.


DosReallocHuge (NumSeg, Size, Selector)


;NumSeg (USHORT) - input : Number of 65536 byte segments requested. ;Size (USHORT) - input : Number of bytes requested in the last non-65536 byte segment. A value of 0 indicates none. ;Selector (SEL) - input : Selector returned on a previous DosAllocHuge.

Return Code

rc (USHORT) - return Return code descriptions are: * 0 NO_ERRORç * 8 ERROR_NOT_ENOUGH_MEMORY * 87 ERROR_INVALID_PARAMETER


DosReallocHuge is called to change the size of unshared or shared huge memory allocated by DosAllocHuge. The selector used for this call must be the one returned by the DosAllocHuge request.

Normally, segments allocated as shared (AllocFlags bits 0 and 1 were set) cannot be decreased in size. However, if AllocFlags bit 3 was also set, the shared segment's size can be decreased.

DosReallocHuge is also called to reallocate a segment allocated as discardable (AllocFlags bit 2 set) after the segment is discarded by the system. The call to DosReallocHuge automatically locks the segment for access by the caller, the same as if a DosLockSeg had been issued.

'Note:' This request may be issued from privilege level 2 or 3. However, only a privilege level 3 huge segment is valid.

Family API Considerations

Some options operate differently in the DOS mode than in the OS/2 mode. Therefore, the following restriction applies to DosReallocHuge when coding for the DOS mode:

The requested Size value is rounded up to the next paragraph (16-byte).

Example Code

C Binding


USHORT rc = DosReallocHuge(NumSeg, Size, Selector);

USHORT NumSeg; /* Number of 65536-byte segments

                                  requested */

USHORT Size; /* Number of bytes in last segment */ SEL Selector; /* Selector */

USHORT rc; /* return code */ </PRE>

MASM Binding


PUSH WORD NumSeg ;Number of 65536-byte segments requested PUSH WORD Size ;Number of bytes in last segment PUSH WORD Selector ;Selector CALL DosReallocHuge

Returns WORD </PRE>


en/docs/fapi/dosreallochuge.txt · Last modified: 2020/12/05 11:44 by prokushev